Carburetor



R. REISTAD March 31, 1953 CARBURETOR Filed Nov. 28, 1949 Patented Mar. 3l, 1953 CARBURETOR Rolf Reistad, Oslo, Norway,

assig'nor of sixty per cent to the firm Francis Sonnichsen, Oslo,

Norway Application November 28 In Norway Dec 3 Claims. 1

The present invention relates to carburetors for internal combustion engines and the object of the invention is to provide a carburetor which may be quickly and easily adapted to engines of diierent sizes, that is, engines having different numbers of cylinders and/or horse powers, and which is economical as regards fuel consumption and at the same time ensures the desired acceleration of the engine under all conditions.

The invention is characterized inithat the jet system comprises a number of sleeves arranged one within the other, and rotatable relative to each other and to a stationary supporting member, which sleeves are provided with a number of communicating ports leading to a well provided with a discharge opening and a port communicating with a supply bore from a float chamber in such a manner that the supply to the sleeves and the carburetion action thereof may be varied by rotating the sleeves in relation to each other and/or in relation to the stationary member.

In order that the invention may be more clearly understood one particular embodiment of the invention will now be described, by way of example, with reference to the accompanying drawing wherein- Figure 1 is an axial section of the carburetor,

Figure 2 is a plan view thereof, and;

Figure 3 shows the jet device in axial section and on an enlarged scale.

The carburetor comprises two cylindrical sections I and 2 arranged concentrically in alignment and together forming the suction pipe and mixing chamber 3. Surrounding the upper end of the section 2 and integral therewith is an annular flange 4 forming a iioat chamber 5 which is covered by an annular iiange B integral with the lower end of section I and secured to the flange 4 by means of screws I. In this manner the annular anges 4 and I5 serve to connect the sections I and 2 tightly together, preferably by an intermediate packing (not shown). At the lower end the section 2 is provided with a ange 8 by means oi which the carburetor is secured to the intake manifold of the engine and the section 2 at its upper end is provided with a flange 9 for supporting, in known manner, an air filter.

Fuel is admitted through a supply duct II the inner end of which is controlled by an inlet valve I 2 carried by a pivoted lever I3 connected with a oat I4.

In the mixing chamber 3 is arranged a preferably replaceable venturi I5 and below this, arranged diametrically in the chamber, an integral lower cross piece I6 with a cross section which 1949, Serial No. 129,784 ember 14, 1948 preferably is tapered upwards in order not unduly to interfere with the downward iiow of mixture. The cross piece has an integral upwardly extending tube I7 arranged axially in the chamber and which is closed at its lower end to form a well. The tube I'I is provided at its upper end with a bevelled end surface which is inclined outwardly and downwardly and projects somewhat above the maximum level of the fuel in the oat chamber 5, as indicated by the line X on Figure 3.

In the tube Il there is rotatably mounted a sleeve i8 and rotatably mounted in said sleeve is a second sleeve I9 which is open at its upper end. At some distance above the end of the tube I1 the sleeve I8 is provided with an annular enlargement 26 which decreases conically upwards as shown. From the underside of said enlargement 2! at a point some distance from its lower end the sleeve I8 has a smaller outer diameter than the inner diameter of the tube Il so that an an'- nular fuel well 2| is formed between said members l'I and I8. The lower end of the enlargement 20 has an outer diameter which corresponds to the outer diameter of the tube I 'I and thus extends outside the opening of the well 2| and thereby forms an annular slot 22 between its under surface and the upper end of the tube Il. Between the tube I 'I and the sleeve I8 there is arranged a packing ring 23 but, as will be understood, thesleeve I8 may be closed at its lower end.

The two sleeves l 8, I9 are provided with a plurality of ports 24 and 34, respectively, arranged in vertical rows and spaced in the vertical direction of the well 2I. The cross sectional area of said ports may, if desired, increase progressively from the upper series of ports to the lower series as shown. A bore 25, leading from the iloat chamber 5 and extending through the cross piece I6, communicates 'with corresponding ports 26 and 36 through the sleeves I8 and I9, respectively.

In the position shown in the drawing, in which the carburetor is regulated for maximum output, the port 26 lin the sleeve I8 and the port 36 in the sleeve I9, and the bore 25 are in alignment and all the ports 24 and 34 in the sleeves I8 and I9, respectively, are also in alignment. When in use, with the throttle 21 in open position and the well 2l, the ports 24 and the inner sleeve I9 lled with fuel to the level X, the suction from the engine draws air from the air intake downwards through the mixing chamber and causes the fuel to discharge through the Iannular slot 22. At the same time air ows downwards through the sleeve I 9, then through the ports 24 and 34, and up- 3 wards through the well 2i. During this operation the air is mixed with and entrains and comminutes or atomises the fuel in such a manner that the fuel mixture discharges from the annular slot 22 in such a comminuted or atomised state that a most suitable mixture is obtained.

The control of the output of the carburetor in accordance with the number of cylinders or the power of the engine is effected either by controlling the degree of atomisation or comminution or by regulating the supply of fuel to the sleeves or both.

For this purpose the sleeves I8 and i9 are provided at their respective upper ends with radially projecting arms or tongues 22 and 29, respectively, to which are secured the inner ends of screw members 39 and 3l, respectively, which pass through the wall of the cylinder l and may be displaced in longitudinal direction by means of the adjusting nuts 32 and 33, respectively,

whereby the sleeves may be relatively rotated about their longitudinal axis.

In rotating the sleeve I8 by means of the screw 32 the port 2B is displaced inrelation to the supply bore 25 and the port 36 in the sleeve I9, and thereby the effective area of the supply bore may be adjusted from maximum to zero. In association with the adjusting nut 32 there is preferably provided an indicating device such as a pointer and a dial (not shown), which indicates the position of the nut for the different adjustments of the sleeves i8 and i9 corresponding to differenttypes of engines.

By rotating the nut 33 the sleeve I9 is rotated so that the ports 24 and 34 in the sleeves I8 and I9, respectively, may be brought into register to a greater or lesser extent, whereby the carburetion action may be adjusted in accordance with the desired conditions. Owing to the fact that the sleeves i8 and I9 are individually rotatable, this adjustment or regulation must be eifected at any position of the sleeve i8 within the range of rotation thereof in order to regulate at the same time the supply of fuel from the iioat chamber.

The annular well 2l is connected by a tube 31 with an idling bore 38 which extends through the venturi i5 and the member 2 into the mixing chamber behind to the throttle 2 when said throttle is in closed or nearly closed position. The discharge from the bore 38 is controlled by an adjusting screw 39.

I claim:

1. In a carburetor, a casing forming a fuel chamber and having a central passageway therethrough, a Venturi element mounted in said passageway and having a bore therein communicating with the fuel chamber, a tube positioned axially of the Venturi element in communication with said bore and forming a mixing chamber, an inner sleeve forming an air conduit rotatably mounted axially of said tube and having rows of holes therein spaced longitudinally along same, and a hole adapted to register with the bore from the iloat chamber, and an outer sleeve also rotatably mounted axially of said tube surrounding said inner sleeve and spaced inwardly from the inner wall of the tube and having rows of holes therein spaced longitudinally along same and a hole adapted to register with the bore from the oat chamber, said rows of holes in the respective sleeves being adapted to register upon relative rotation of said sleeves and said latter holes in the respective sleeves being also adapted to register upon relative rotation of the sleeves to control the flow of fuel from the float chamber to the inner sleeve.

2. In a carburetor, a casing forming a fuel chamber and having a central passageway therethrough, a Venturi element mountedin said passageway and having a bore therein communicating with the fuel chamber, a tube positioned axially of the Venturi element in communication with said bore and forming a mixing chamber, an inner sleeve forming an air conduit rotatably mounted axially of said tube and having rows of holes therein spaced longitudinally along same, and an outer sleeve also rotatably mounted axially of said tube surrounding said inner sleeve and spaced inwardly from the inner wall of the tube, and having rows of holes therein spaced longitudinally along same, said rows of holes in the respective sleeves being adapted to register upon relative rotation of said sleeves, and said outer sleeve having thereon a frusto-conical section the wall of which cooperates with the Venturi element to form the fuel mixture passage through the latter and the bottom of which cooperates with the top of the tube to form a restriction for limiting the flow of the fuel mixture through said passage.

3. In a carburetor, a casing forming a fuel chamber and having a central passageway therethrough, a Venturi element mounted in said passageway and having a bore communicatingr with the fuel chamber, a tube positioned axially of the Venturi element in -comunication with said bore and forming a mixing chamber, an inner sleeve forming an air conduit rotatably mounted axially of said tube and having rows of holes therein spaced longitudinally along same and a hole adapted to register with the bore :from the iioat chamber, and an outer sleeve also rotatably mounted axially of said tube surrounding said inner sleeve and spaced inwardly from the inner wall of the tube and having rows of holes therein spaced longitudinally along same and a hole adapted to register with the bore from the float chamber, said rows of holes in the respective sleeves being adapted to register upon relative rotation of said sleeves and said latter holes in the respective sleeves being also adapted to register upon relative rotation of the sleeves to control the fiow of fuel from the float chamber to the inner sleeve, and said outer sleeve having thereon a frusto-conical section the wall of which cooperates with the Venturi element to form the fuel mixture passagethrough the latter and the bottom of which cooperates with the top of the tube to form a restriction for limiting the ow of the fuel mixture through said passage.

ROLF REISTAD.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,022,702 Rothe et al. Apr. 9', 1912 1,254,659 Coulombe Jan. 29, 1918 1,606,491 Abernethy et al Nov. 9, 1926 1,893,896 Heftler Jan. 10, 1933 FOREIGN PATENTS Number Country Date 177,197 Great Britain Mar` l2, 1922 258,843 Great Britain Sept. 29, 19271 

